ADLINK Technology NuDAQ ACL-8454, User Manual

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Installation
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17
2.9 Clock Source Configurations
For every independent counter, four signals can be chosen as clock
source by jumper setting. The clock source of counter #n comes
from either
CLOCK1 , CLOCK2 , the external clock source ( ECLK n ),
or the cascaded counter output. Note that the clock source of the
cascaded counters (counter #5, #6, #11 and #12) are fixed.
CLOCK1
CLK n
COUT x
CLOCK2
ECLK n
Figure 2.12 Clock Source of Counter #n
The two internal clock sources,
CLOCK1 and CLOCK2 come from
the clock system (see 'Clock System section'). The cascaded clock
source comes from the output of the counter with smaller channel
number. For example, the
COUT1 is cascaded to source of CLK2 ,
the COUT3 is cascaded to source of CLK4 . The exceptions are the
cascaded source of CLK1 comes from COUT4 and the cascaded
source of CLK7 comes from COUT10 .
The external clock source named as ECLK n comes from the 37-
pins connector. Figure 2.13. demonstrates the clock source jumper
setting counter channel 1 (
CLK1 ) by jumper ‘ CK1 ’. In this figure,
the clock source comes from the internal source CLOCK1 .
Sources of CLK1 (by setting jumper CK1)
CK1
I
IV III
II
I: CLOCK1
II: CLOCK2
III: LAST CHANNEL (COUT4)
IV; EXTERNAL (ECLK1)
Figure 2.13 Setting the Clock Source of Counter #1
The jumper setting is flexible for user applications. There are four
kinds
of configurations for every clock source jumper.